The present invention relates to an innerboot, such as an innerboot for ski boots, with improved fit.
The provision of the greatest possible comfort for the user is currently strongly felt in the field of footgear and in particular in the field of ski boots.
On this subject, in known boots it is common to use innerboots, the function whereof is to place the skier's foot in contact with soft surfaces and thus not directly in contact with the shell or with the quarters, which are notoriously rigid.
Traction elements or cables are used in known boots; on one hand, when they are tensioned, they create an empty region between the boot and the innerboot, and this does not allow the skier to optimally transmit the effort from the foot to the boot.
On the other hand, said tensioning causes the cable to act in localized regions of the foot, thus not allowing the uniform securing of said foot, and this again leads to a non-optimum transmission of the efforts to the boot.
In order to optimize fit and the skier's comfort, innerboots are known which are internally provided with a cavity inside which material is injected when the boot is closed.
This injection allows to achieve a modeling of the innerboot according to the anatomical configuration of the foot, but at the same time it has been found to have some disadvantages: it has in fact been observed that said injection compresses the foot, especially in particular regions such as that of the plantar arch, making skiing awkward, since the innerboot thus obtained has a non-yielding shape and thus has regions which cannot deform and are therefore not suitable for optimally following the various positions assumed by the foot while practicing the sport.
So-called "flow-fit" innerboots are also known which contain, inside them, a particular putty which, under the pressure of the foot, migrates inside the innerboot which thereby assumes an internal configuration equal to that of the foot inserted therein.
However, even this solution has disadvantages, since it has been observed that in the course of time said putty contained within the innerboot tends to pack, thus lacking in one or more regions and thus cancelling out any possible region of comfort.
It has been furthermore observed that an excess amount of putty inserted in the innerboot entails an excessive overall compression of the foot, and vice versa a limitation of the amount of putty allows the foot to "wobble" inside the innerboot.
Finally, it has been observed that the considerable stresses imparted by the foot while practicing the sport constantly move around the putty placed inside the innerboot, and this places one or more regions of the foot in contact with the shell.
Ski boots are also known which comprise air bags which are arranged between the boot and the innerboot and are inflated directly by the skier.
The disadvantage of said air bags is that they require, for correct use, to be inflated at high pressure, and this entails the subjection of localized regions of the foot to pressures which limit blood circulation like a tourniquet and thus lead to the forming of aches and to lack of sensitivity of the foot while practicing the sport.
The compressibility of the air further allows the foot, in some regions, to touch the boot while practicing the sport.